NoseyNick's (G7RZQ's) Elecraft K2

"I don't know if anybody else [...] does this, but every time I turn my
K2 on, and use it on a DX-ped hour after hour, I sit and look at this
itty bitty radio, and am just amazed at how something so small, can be
so good! anybody else do this?"

Yes. This is normal behavior.

-- K7ZUM and KZ1X, Elecraft Reflector Mailing List

I have neglected my Amateur Radio hobby for too long. In the
intervening time, licensing has changed and I'm now allowed to use the
HF bands. In an effort to get back into the hobby, and particularly
onto HF, I have decided to buy and build an Elecraft K2 kit.

Yes, it's a kit. I get to build a really respectable HF Amateur
Radio transceiver, with top-notch performance, for about a third of
the cost of anything vaguely comparable, though obviously I have to
invest a lot of my precious TIME too. At the end of it, I end
up with a radio that I UNDERSTAND, not a sealed box of
unexplained tricks made in the far east using technology I'm unlikely
to be able to tweak or repair.

I decided to put together this page to document the entire process
from start to finish, in case it helps anyone else.

Contents

Well, first I was drooling over an Icom 756
pro with all the pwetty gwaphs and colour displays and stuff, but
I knew I couldn't afford it until I win the lottery. The 746 pro
was another option, but still cost far too much, and anyway, both of
these are mass-produced manufactured boxes of tricks, there's none of
that experimental spirit of Amateur Radio

At some point I became interested in the "Tayloe Detector" I'd read
about in an article somewhere. It might have been "A Software-Defined
Radio for the Masses, Part 1" found on ARRL's SDR page. This
is a fantastically neat little detector (the main core of a receiver)
which I could understand. I'm mostly a digital chap, I understand ones
and zeros, and all the analogue stuff with non-linear mixers and
bandpass filters and beat frequencies and things scare me, yet the
Tayloe Detector pretty much de-multiplexes your radio frequency into 4
buckets representing 4 phases of the signal you're tuning. It's
analogue, but it's simple analogue that digital geeks can understand.
This could be a receiver I could build myself, and then I could write
software to do most of the rest of the pretty displays and decoding
data modes and everything...

... except it's not even a whole receiver, let alone a transmitter
too...

Then I found that the "Tayloe Detector" wasn't actually some brand
new invention, it's otherwise known as a "commutating mixer" or a
"differential quadrature switched mixer", maybe a "multi phase
sampler". Also, of course, it's "only" a mixer, not a whole receiver,
and definitely not a whole transmitter as well. I was looking forward
to Dan Tayloe's transceiver coming out as a kit, but it was taking too
long, it was CW-only, 20m or 30m only, QRP (low power) only, and
whilst exploring around, I discovered a graph in a
presentation by Dan Tayloe comparing performance versus power
drain of many transceivers including Dan's prototype, the Elecraft K2,
the ten-tec
orion, and various "YaeComWood"
bits of kit. The Ten-Tec one looked to be the best performer (apart
from Dan's rig of
course), better than the Icoms I was previously drooling over, but
eats power and costs a fortune.

The K2... Hey, here's an interesting one, performs damned well
(almost as well as Dan's CW-only rig), doesn't eat juice too much, SSB
option, all major amateur bands, comes as a KIT, and (thus?)
costs considerably less than anything anywhere near its class. It
seems you could easily pay 3 times as much for a rig that would
perform far worse!

I've built electronic gizmos before, including stuff I designed
myself and stuff in ready-made kits. This wasn't going to be trivial,
but sounded like fun!

So I can't wait for Dan's rig, which seems to be CW-only (Morse)
anyway. The "second best" rig (the orion) costs a fortune and eats
power. The "third best" rig is the K2, uses more power than Dan's, but
nowhere near as much as the big shiny boxes, it costs a fraction of
the big shiny boxes, and outperforms most of them. What's the catch? I
need time to build it myself, and hey, I might even UNDERSTAND
IT after I build it bit by bit! Fantastic!

Well, I exchanged a few emails with their webmaster, and then
decided to turn up to EARS one week. They had a GSM talk, which is
related to my work, and I had a good chat with some of the guys there
too. A week and a bit later, I went to their Field Day - basically one
of the competitions like the one above. They set up a big tent, 2
masts, a vast antenna and a rig, and then for 24 hours, you try to
talk to as many other hams around the world in as many countries as
possible on as many bands as possible. The scoring is complicated but
involves counting the number of contacts and multiplying up by all
sorts of things. Sometimes one contact can earn not only a couple of
points, but hundreds because it's also multiplied your total by 2! It
was a lot of fun, it was also a great way for me to learn a bit more
about the K2 and its options, and operating HF (or contesting at
least!). I became a lot clearer about what bits I need, what bits I
don't need, etc etc.

I joined the Elecraft
reflector - a mailing-list for owners, builders, and potential
owners of Elecraft Kit - the K2, K1, KX1, etc etc. Way too many posts,
but quite a few of them are useful!

Better solder? "Elecraft recommends 60/40". Solder is
cheap, and nice new solder is bound to work better than the crummy
aged stuff I'm using, which quite possibly belongs to a plumber
rather than an Electronics constructor. EU RoHS directives are
phasing out lead though, so I'll
probably have to go for a lead-free alternative. Nigel G8IFF said
"You go buy lead free solder, preferably silver loaded, and start
using it. No changes needed to your normal soldering methods".
Multicore? .015 dia probably easier than .032

Antistatic strap? I've usually got away with
touching something earthed, but again for a project of this
magnitude, it might be worth investing in - they're not expensive,
and may save me a load of re-ordered parts.

A DMM that'll do resistance and capacitance, maybe even
inductance? I have an old analogue meter which manages resistance,
manual ranging and everything, but it won't help me check
capacitor values and it's a bit inaccurate even at resistance.

KAT100-1, or possibly pic-a-tune or something: An ATU. I don't
have space in my garden for a properly tuned antenna, and such an
antenna would also be tuned for "the band of my choice" and I
don't yet know enough about the bands to choose only one, let
alone one that would fit in my garden. No, seriously, random
length of wire, as much as I can get away with, and an ATU to make
it work properly. Got to be the way to go.
Something to consider: the KPA100 and kat100 can be built into a
separate EC2 enclosure as
shown by kk7pand ki6wx.
This allows the k2 to be built with all the QRP options including
internal battery, and to be run as a QRO (full power) base station
by plugging into the KPA100/kat100 when at home.

ETS15 or ETS2 tilt stand? 1.5" for KAT100 or or 3" for EC2? Sounds
like the K2 comes with one, but might need one for separate
EC2/KAT100? (Maybe later)

Main order?

Elecraft ETS15 $11.50Elecraft ETS2 $11.50

☒

FDIMP Finger Dimple - just makes tuning up and down the
bands a bit easier.

Main order

Elecraft FDIMP $4.50

☒

A 50 ohm dummy load (possibly DL1?) rated for at least 10W

When testing K2

Elecraft DL1 $25.00

N

"External wattmeter" OR dummy load above may allow
voltmeter to be used as a wattmeter

When testing K2

(DL1+DMM)

☒

A Noise generator.
Useful for testing and aligning the K2's filters

When testing K2

Elecraft N-GEN $39.00

☒

A Test Oscillator, useful for setting S-meter level

When testing K2

Elecraft XG1 $39.00

☒

Proset-K2 or similar: A headset with mic, so I can listen
to radio squawks and squeals without disturbing the family, and
also easy enough to use as the primary microphone. It's what
everyone seems to use these days. Handheld mics take one too many
hands which are better used for writing and typing. Desk mics
really don't cut it either. The K2 has a Kenwood-style 8-pin mic
connector.

My PSU (Power Supply) is inadequate, Should be OK for basic K2 -
13.8V, 5-7A. K2 comes with a suitable plug to make a power cable. I
guess I'll need a few more amps if I want to get much out of the
KPA100 though - 20A 13.8V! Preferably linear rather than
switched-mode but linears are huge and expensive, and switched are
small and (comparatively) cheap. Maybe MyDEL
MP-4128 or similar?

When I eventually get around to
learning Morse,
(g4fon has a good Morse tutor too),
(good paddle use),
I'll need a Morse key / paddle.
"Llaves Iambic Paddles. Gold plated, excellent, less than $100,
shipped!" (says W2AGN).
Kent Paddle Kit KIT - allegedly one of the best keys you can buy.Black Widow Paddle, from W5JH who designed the AZ ScQRPion paddle
- looks nice, recommended on Elecraft List, and A KIT!
A suitable plug is provided with the k2 kit.

I asked around on the Elecraft reflector, and contacted a few
friends who know a bit about importing stuff from the US to the UK. It
sounds like there are some "commodity codes" that can be put on the
customs forms on the parcels:

These should legitimately get your parcel zero-rated for
customs+excise duty. VAT is still most likely to be payable on
anything purchased from outside the EU. There are Elecraft resellers
in the EU, but they'll charge their own local VAT, which
(depending on how weak the dollar is, and how high their local VAT is)
may easily end up costing more than ordering from Elecraft
themselves. It's also worth noting that parcelfarce will also
charge an admin fee for collecting the VAT, and have also apparently
frequently cocked up and wrongly charged duty, which then needs to be
reclaimed following a long and laborious process that can take 3
months. UPS and similar carriers usually get it right, but obviously
also cost more in the first place. :-(

If your kit is being bought for a VAT-registered company, it might
be possible to pay 0% VAT too, but it seems unlikely that
amateur radio kit can legitimately be claimed to be for
professional use.

Built XG1 with Pb solder. First time I've
used my new soldering iron. Takes a little practice, but very very
good once it gets going.

2005-12-15

Built DL1. Tried AgSnCu solder. It's really
quite bad stuff! Needed quite a lot more heat, quite a lot more time
with the iron in contact with the components, lucky these are mostly
just high-wattage resistors! I suspect I'll be using Pb for K2 itself

2005-12-15

Built N-gen, unleaded solder again.
Starting to get used to it, but still prefer the Pb stuff.

2005-12-15

Built BL2, part leaded, part unleaded. Yup,
I'll do the K2 with lead, stuff RoHS!

2005-12-16

Started K2 control board

2005-12-18

Completed K2 control board, most of front
panel

2005-12-19

Completed front panel, and RF stage 1, got
to that fantastic moment where you power it up and it says
"ELECrAFt" in the display!

2005-12-24

Some of RF Stage 2 - mostly resistors and
capacitors

2005-12-26

Almost all of the rest of RF Stage 2,
including the terrible toroids!

2005-12-27

Finished RF stage 2, did some alignment
stuff, heard the Lake District on 40m using only an un-tuned spool of
solder as my antenna!

2005-12-29

Finished RF stage 3, and TX alignment into
DL1

2005-12-30

Last few bits of hardware assembly.
K2 #5209 is complete!

2005-12-31

Posting to the Elecraft
reflector, resting, and then hanging some copper in the sky.
Random length of wire diagonally across the garden for the moment.
Also checked calibration using RWM on 9996kHz - an
atomic clock frequency reference in Moscow- after advice from David
G4DMP and Sverre LA3ZA. I seem to need to tune 180Hz up. Will fix
later. Programmed the IARU
beacon frequencies into RCL 1-5 and RWM into RCL 0.

2006-01-01

Listening to special event station GB1MGB
for Guide Dogs whilst
reading the KSB2 manual

2006-01-02

I seem to have a low power problem. Low
power out, low current drain on the PSU, so something's not providing
enough power to the later PA stages. I tried to go through TX
diagnostics, by my only "signal generator" is the Elecraft XG1,
capable of 50uV out, not 0.14V required by Appendix E. :-(

2006-01-03

Dug out an old valve-driven sig-gen and
played with it. Better than XG1, voltage-wise, but still not
great.

2006-01-04

Could kick myself. Borrowed a much shorter
2m bit of much nicer-looking ex-10base2, and put DL1 on the other
end of THAT instead of the ropey old 25m bit which I'd previously
been using (seemed like a good idea at the time - it was all I had).
K2 is fine, I've just wasted lots of testing time that could have
been building time.

2006-01-07

Built most of KSB2. Arranged to borrow an
ATU from Stuart@EARS so I can test TX BEFORE KPA100 +
KAT100

2006-01-08

Finished KSB2, but found a problem with my
BFO, meaning I couldn't CAL FIL properly.

2006-01-09

Fixed BFO, not sure how, probably a
dry/cold joint caused by the KSB2 rework, but touched most of the
BFO-related solder joints with the iron, and re-tested OK.
Re-installed KSB2, made some patch cables and things to use Stu's
ATU. Theoretically ready to transmit!

2006-01-10

Slightly worried - can't hear RWM on 9996.
Have I knackered my K2? Do I have to go through all that
troubleshooting stuff again?

2006-01-12

Can hear RWM again - phew! Presumably I
have a lot to learn about 10MHz propagation :-/

2006-01-14

RE-calibrated VFO - now within about 30Hz

2006-01-14

Made my first ever HF QSO, with
Justin G4TSH from EARS (yeah, so just the other side of Staines),
just before the RSGB AFS contest. Heard his CQ, recognised the call,
couldn't resist. Should probably have asked him to be a bit more
critical of my audio etc, but had "first QSO" nerves and rushed it a
bit, then left him to enjoy AFS while I went to my daughter's
birthday party. Sounds like he'd managed over 17 contacts in the
first 7 minutes though - he was storming along!
2006-01-14 13:54 3696kHz

2006-01-16

Started a bit of KPA100

2006-01-18

Little more KPA100

2006-01-21

Fair bit more KPA100

2006-01-22

Bit more KPA100, including the initial
tests where it plugs into the K2, clicks a bit, and adds some menu
options.

2006-01-28

KPA100 toroid winding

2006-01-29

Little more KPA100

2006-02-10

last few KPA100 toroids wound

2006-02-12

Heard that Dennis, G3KKQ, from EARS, is a
silent key. He had been struggling for a while after a collapsed
lung. Not sure if he realised he was one of the reasons I chose the
K2. He will be missed.

Played with baudline Linux spectrogram
software. Can read Morse dits and dahs vertically off the screen.
Quite a laugh. I'll use this for precision re-calibration at a later
date.

2006-03-17

Designed most of my QSL card

2006-03-18

Finished my QSL card

2006-03-23

Discovered I have a "known issue"
whereby the K2 goes deaf when I turn AGC OFF. Will investigate AGC
components a bit more, but it looks like I need to replace "5.068MHz
AGC crystal" X1

2006-03-25

... on the plus side, discovered that my
NGEN works fine if given a decent voltage power supply, just not on
a nearly-flat 9V NiCad.

2006-03-26

YAY! Fixed the AGC: If you are seeing AGC
problems (hold PRE/ATT and AGC, see if your K2 goes deaf), check
your junk box for a 10pF cap and change control board C8. Wayne says
680 pF at C7 may be another option. I DO NOT recommend this mod
UNLESS you're seeing "AGC OFF" issues though.

2006-03-28

Played with Voice Over IP - VoIP. I can now
listen to my K2 from anywhere in the house over my wireless
ethernet. Now I need to sort some remote control software, so I can
operate it.

2006-04-12

Had a play in the RSGB SSB 80M Club
Championships. Did really badly, proved the K2 works, but not great.
Probably ought to get around to that re-calibration, and work on
getting some more copper higher in the sky - my random unbalanced
wire is hardly ideal.

2006-05-23

Started to write a simple perl K2 serial
terminal, which decodes what you're sending and recieving to the
K2.

Ordered a
Black Widow paddle.
I'll have to build it, then I'll have to learn morse :-)

2006-06-26

Jerry thanks me for my order, lets me know
he's missing some springs but will ship as soon as he can find some
more.

2006-07-08

Black Widow arrived. No silly duty or VAT
or anything to pay.Tried polishing the base with brasso,
without first sanding, at the advice of my father-in-law. Didn't
work at all well, could still see manu

2006-07-09

Made a couple of contacts with GB5HQ - RSGB
stations in the IARU contest.

2006-07-10

Tried sanding the Black Widow base. Spent
hours with a bit of sandpaper on a flat surface, as per
documentation, then tried the buzzy electric sander and got a
splendid finish within a minute or two. It's now covered in lots of
tiny little swirls, very pretty, matt finish, but I'll probably go
for finer polishing until it's mirror-like.

2006-07-12

Missing some parts from Black Widow. Let
Jerry know. He's going to pop them in the post tomorrow.

2006-07-16

Spent some of the last few days sanding and
sanding this thing. Spent today assembling most of it. Still need my
hex spacers.

KPA100 unfortunately required before KAT100 because KAT100 needs
the KIO functionality (AUXBUS)... So had to borrow Stu's ATU,
otherwise I'd have had to build K2 without testing transmit, KPA100
without being able to test transmit, then KAT100 and be able to
transmit into a tuned antenna :-/